Piles or columns supporting a vertical load can deteriorate over time, particularly in marine environments. Tides, water currents, salt water abrasion, floating debris, marine insects, wide temperature gradients, and weathering all contribute to deterioration of the column while the column bears a continuous load. Bridges and docks are examples of architectural structures that are supported by columns in marine environments. Columns can be made of concrete, steel, or wood, for example. Deteriorated columns, or more generally, weight bearing members, are typically repaired in place because of the high cost to remove each column for repair or replacement. Marine column restoration is a dangerous and arduous process because the columns often extend several feet under water and are difficult to access. Further, rehabilitating marine columns often must be done quickly because much of the repair takes place while under water. Occasionally, the repair site must be “de-watered” to prevent water from interfering with the column restoration.
Shells or jackets have been introduced to protect columns from further deterioration. Shells are designed to surround the column above and below the area of deterioration. A shell is placed around the column and then grout or an epoxy is poured or pumped into the space between the shell and the column. The shell provides a permanent form that protects the column from further deterioration while retaining the epoxy or cementitious that fills the voids in the column. The epoxy or grout or epoxy also prevents water or environmental corrosives from contacting the damaged portion, or any other covered portion, of the column. However, little structural capacity is added to the column by the shell and epoxy grout combination.
Shells that can both increase the structural capacity of columns and at the same time protect the columns from deterioration are desirable in many situations. For example, bridges that were built several decades ago may be supported by columns that were designed to support smaller loads and comply with less stringent design standards than are required by today's code standards. A bridge built in 1950, for example, may have been designed and built to support trucks up to 40,000 lbs, and would need to be enhanced to support the heavier trucks of today, increased traffic, and more stringent structural codes. Moreover, the columns supporting such a bridge may have deteriorated over time such that the weight-bearing capacity of the bridge has decreased.
Conventional shells are unable to substantially increase the structural capacity of weight bearing members because they do not have positioners, bar supports, or reinforcing members integrated thereon. The present invention has been found to solve many problems inherent in conventional shells and column-restorative procedures.